Bowl separator



Feb. 20, 1934. C. E. G|5H 1,947,844

BOWL SEPARATOR Filed March 2:5, 1951 5 sheets-sheet4 1 Illnlllllf Z5 4 Il' IIIl lll' III I IH'- l 1li /sg'/ 52 'MMIII' n Y 55 l /f I gl.

Feb. 20,V 1934.

` Filed March 23. 1931 C. E. GISH BowL sEPARAToR 3 Sheets-Sheet 2 "I Z yff .5 /g /9 f, wf m Feb. 20, 1934. E G|$H 1,947,844

BOWL SEPARATOR Filed March 25, 1931 sgsheets-sheet s /4 W Z 7a 9 f4 'il' I 4' o /f/// 'Ih /0 V 8b 6 if '0 Ih ia l l .54a i /ja Patented Feb. 20, 1934 UNITED STATES PATENT oI-FicE BOWL SEPARATOR Chase E. Gish, Denver, Colo. Application March 23, 1931. Serial No. 524,541

19 claims. (c1. 23a- 27) This invention relates to bowl separators and has for an object the provision of improved means for recovering'or making a clean-up of the material caught by the rimes in the operation of such an apparatus.

A further object of the invention is to provide an improvement in bowl separators whereby the rifes are separable from the bowl.

A further object is to provide improvement in the contour of the interior of the bowl whereby to render the same more ecient inthe recovery of various classes of material and values.

A further object is to provide improvements in such a separator whereby the various grades of material recovered thereby maybe substantially separated and classified and further improvements whereby such substantially separated classes of material may be separately recovered.

A further object is to provide improvements in the structure of such an apparatus whereby the rimes may be more easily and cheaply constructed and whereby they may be readily renewed or replaced when worn or damaged.

A further object is to provide in such an apparatus an improved construction and arrangement of launders and associated means for receiving and disposing of the waste material and for receiving, retaining and safeguarding the values coming from the machine in the clean-up.

.A further object is to provide a bowl separator which shall be of great efficiency in operation and shall be durable and cheap as to manufacture, operation, maintenance and repair.

The foregoing objects will be amplied and other objects will appear in the following specifi-v cation, taken in connection with the accompanying drawings, in which like characters of reference indicate corresponding parts throughout and in which Figure I is a rear elevation of the apparatus, portions being broken away and portions being shown in section, exclusive of the settling tank.

Figure Il is a side elevation,v portionsl being broken away and portions shown in section, including the settling tank.

Figure III' is a sectional view showing the parts of the bowl and rifes in operative position for separation of materials.

Figure IV is a view the same as Fig. 3 butV showing the riflle basket raised fork the clean-up operation.

Figure V is a sectional view of a modied construction wherein the riflles and bowl are arranged a plurality of separate sets and sections. Figure VI is a fragmentary view of the ernbodiment shown in Fig. 5, illustrating the'posiy' tion of the parts when one of the sets or sections of riilles is in raised position for a clean-up of the upper portion of the apparatus.

Figure VII is a view the same as Figure 6 but illustrating the position of the parts when all sections of the rimes are raised for a clean-up of all portions oi the bowl. y A

In the operation of bowl separators certain objections and difficulties have been encountered, among which are the difficulties and expense incident to thecutting of riles in the inner surface of the bowl; the necessity of stopping the bowl and washing out the riles in order to accomplish a clean-up; the difliculty and expense of making repairs or replacement when the riiiies become worn or damaged; the diiculties of` making complete or efficient recovery of the values from the materials treated;A the difficulty of separating or classifying the diiferent values where the material treated contains different kinds of values and the difliculty of separately recovering in the clean-up, the different classes of values caught and retained in the riilles at different sections of the bowl.

The present invention is designed to eliminate,v

remedy and/or lessen the diiculties and objections encountered in the operation of bowl separators now and heretofore in use, including those above mentioned.

In providing an apparatus according to this' invention, many variations -in the details of construction may be made and I dc not wish tobe limited to the details of the structure as herein described or as shown in the accompanying drawings, which are for the purpose of illustration and not intended as a definition of the invention, the' order to keep contained material f-rom settling at the center of the bowl around the shaft.

The interior surface of the bowl is preferably smooth but for the purpose of catching and retaining the value s from the material treated within the bowl, I provide a basketlike structure having an external contour corresponding to the internal contour of the bowl and comprising a series of rings 'I attached to straps 8, supported 17 may slide up and down by ring 9, which ring is mounted ior movement and may seat upon the 'upper rim of the bowl as illustrated in Fig. 3 or be raised thereabove as illustrated in Fig. 4.

The straps 8, below the ring 9, conform to the contour of the inner surface of the bowl, so that when the ring 9 is lowered to the position shown in Fig. 3 the straps 8 will t snugly against the inner surface of the bowl. VThe straps 8 may be mortised into the outer edges of the rings 7 and secured thereto by any suitable means, as by welding, and the outer edges of the rings 7 are formed so as to snugly fit against the inner surface of the bowl when lowered to the position shown in Fig. 3, in which position the rings, which preferably have a flat, horizontal under surface, will form a series of rililes on the inner surface of the bowl. f Y

The ring 9, in lowered position is designed to t tightly upon the top edge of the bowl, as clearly illustrated at Fig. 3, and at the joint thus formed there is preferably provided a gasket 10 of any suitable material for cushioning the ring 9 as it is lowered onto the bowl and for tightly 'closing the join-t therebetween, so that, in

lowered position, ring 9 in effect forms an extension of the bowl and becomes the rim thereof.

The lower inner edge of the ring 9 is preferably of less diameter than the top or rim of the bowl l whereby to form a flange 11, which flange both serves as a rilile to catch and retain values from the material being treated when the `bowl is operated in the position shown in Fig. 3 and provides suitable means for the support of the -riille basket above described, and upperends of the straps 8 being bent over the edge of, and engaging, the said flange as. clearly illustrated at Figs. 3 and 4, whereby the said riiile basket conveniently engages and is carried by the ring 9. Straps 8 may be fastenedto ring 9 by any suitable means as by rivets 8b.`

The means for raising and lowering the ring 9 and therewith the riiile basket comprises rods 12 slidablethrough the circular apron 13 of the 'bowl 1 and having their upper ends threaded into the apron 14 of the ring 9 as at 15, or otherwise suitably secured to said apron 14. The rods 12 are'supported by the arms 16 of a bracket, the central portion of which is designated as 17, said arms being attached to the rods 12 by any suit- Y able means, as by locknuts 18 and 18a.

The central portion 17 of the bracket is provided with a central orifice 19 and a plurality of orifices 20 which may be separated from said -central oriiice. Legs 21 depend from the bottom of the bowl and project through the orices 20, whereby, acting inl cooperation with the apron 13, which slidably engages the rods l2, the whole structure, including the bracket, the rods 12, the ring 9 and associated parts, will be steadied and braced so as to revolve in substantially rigid relation with the bowl. It will be understood, however, that the legs 21 are slidable within the orifices 20, so that the central portion ofthe bracket upon or in relation to the legs 21.

- Resilient means, as coil spring 22, may be interposed between the bottom of the bowl `and the central portion 17 of the bracket whereby the bracket is normally forced downward and the ring 9 is normally held tightly against the upper rim of the bowl 1.

On a suitable support, as crossbeam 23, carried by standards 5, I mount a bracket 24 and therein pivotally mount. as at 25, a lever 26,

vertical upon the inner end of which lever I pivotally mount, as at 27, a block 28 carrying, on its upper side, the lower half 29 of a ballbearing, the upper half of which bearing, being designated as 30, rests upon the balls in said bearing and carries a cone 31 adapted to project into the central orifice 19 and to engage the lower edges of the said orifice when the lever 26 is depressed. It will be apparent that on further depression of the lever 26, the bracket 17-16, the rods 12, ring 9 and riiiie basket will all be raised to the position shown in Fig. 4, thus raising the rings 7 away Vfrom the inner surface of the bowl 1 and leaving a space along the inner surface of the bowl for the free passage of material, as indicated at the arrows in Fig. 4. The cone 3l entering the orifice 19 centers the bearing assembly relative to the bowl so-that the upper half 30 of the bearing, being engaged with the revolving bracket by means of the cone 31 pressed into orifice 19, will yrevolve upon the balls without vibration.

Beneath the apron 14, I provide a launder 32,

with cover 32a and spout 33 for conducting theA overflow from the not shown. p j

Within and below the launder 32 and beneath the apron 13, I provide a second launder 34 having a spout 35, said launder being adapted to catch the overflow escaping over the apron 13 during the spout 35, whence it is conveyed to the settling tank 36, hereinafter more specifically described.

Thernodication illustrated in Figs. .5, 6 and 7 may be generally described as the same as'the apron 14 to any desired point,

structure hereinabove described, except that the I bowl and riiile basket are formed in separable Asec-- tions so that one or more annular sections of the bowl and basket may be provided between the bottom or main portion of the bowl below and the ring 9 above. v

Each of said annular sections of the bowl being vertically separable from the Vportion of the bowl immediately therebelow and the section of basket within said section of bowl being raisable out of contact therewith in substantially the same manner as ring 9 and thebasket are raised as hereinabove described and a separate launder is provided for each such interposed section. More specifically and referring to the illustrative drawings Figs. 5, 6 and 7, the bowl 1, rings 7, straps 8, ring 9, aprons 13 and 14, rods 12 and bracket 16-17 are the same as in the above described embodiment. Between bowl l and ring 9 I provide an annular section 1a adapted to normally seat upon the rim of bowl in a manner similar tothe seating of ring 9 on the rim of bowl 1 in Fig. 3 and provided with a gasket 10a corresponding in structure, relative position and purpose with the gasket 10 of the ring 9. The bottorn of section 1a preferably has a smaller` diameter than the upper rim of the bowl, normally adjoining the section la, whereby a rim or rilile 11a is formed in the saine manner as hereinabove described with regard to the rim or riie 11, formed by the ring 9. The section lo is likewise provided with an apron 13a, similar in structure and purpose to the apron 13 of bowl l. A launder 34a is provided for catching the material flowing out over the apron 13a in the same manner that launder 34 catches the material flowing over the apron 13, said launder 34a being positioned intermediate the launders 32 and 34, as clearly illustrated at Fig. 5. The launder 34a may have a spout and settling tank corresponding to the spout 35 and settling tank 36 provided in conkclean-up and to deliver the same -to the nection with launder 34 and inY view of the disclosureof such spout and tank in Fig. 2 the corresponding spout and tank for launder 34a are not shown, as the illustration would be the same as vthat of spout and tank 35 and 36.

Over the edge ofsection 1a the upper ends of the straps 8 are bent so as to engage the section 1a and be lifted therewith in the same manner that the straps 8, shown in Figs.,3 and 4, engage and are lifted with the ring 9. Accord ingly, when section la is lifted, the riffle basket within the bowl 1, will be lifted out of contact with the bowl in the same manner as illustrated in Fig. 4 and as also specifically illustrated in Fig. '7.

Within section 1a is another rile basket, coinposed of a series of'rings 7a attached to straps 8a, engaging the ring 9, in the'same manner as the straps 8 engage the ring 9 in Figs. 3 and 4.

The rods 12 slide through the aprons 13 and 13a and are suitably attached to the apron 14, the same as in the construction heretofore described with one exception, namely, that a collar 12a is positioned upon the rod 12 at a suitable distance below'the apron 13a so that the rod 12 may be raised some distance without bringing the collar 12a into engagement with the apron 13a but when the rod 12 is further raised, the collar 12a will engage the underside of the apron 13a and lift section 1a away from the bowl l and therewith will lift the riie basket away from the walls of bowl 1. It will, therefore, be evident that by the structure illustrated in Figs. 5, 6 and 7, upward movement of the rods 12 will first lift the ring 9 4away from section la and therewith will lift the riflie-basket in section la andy that thereafter if the upward movement of the rods 12 be continued, section 1a will be lifted away from bowl l and the rile basket in bowl 1 will likewise be liftled. The two lastV described operations illustrated respectively at Figs. 6 and '7.

In Figs. 5, Gand 7 I which may be used for the bowl l and likewise for the section la, which lining may be of rubber or other suitable material and which may be replaced readily in case of wear or damage. This lining maybe used in any embodiment.

The settling tank 36 may be of any suitable shape for receiving material from the launder 34 and permitting the solids to settle therein, but the tank is provided with a cover 38 which may be hinged to the tank, as at 39, and provided with a suitable lock 40, whereby the same may be locked Lto prevent tampering with the contents of the tank. This is an important feature because the theft of values recovered in concentrating apparatus of various kinds is quite common and is difficult to provide against. With the structure here shown it will be noted that there is no opportunity whatsoever to tamper with the values because the bowl continues in the rotation from the time the material is fed into it until after the basket is lifted and the concentrated material is thrown out over the apron into the launder and thence into tank 36, which is locked.

It will be obvious that there is no opportunity to tamper with the concentrated material either in the bowl, along the launder 34 or spout 35, botn of which are closed, or in the tank 36 which is locked. It will be noted that the cover 38 is spaced away from the tank as at 4l, a suicient distance to permit water to overflow so that the capacity of the tank is limited only by the amount of settlings therein and not by the total amount of material received from the launder.

have indicated'a. lining 3'1,Y

In Figs. 1 to 4 it will be noted that I have provided a break in the contour of the inner surface of the bowl as indicated at 42 and it will be noted that the contour of the inner face of the bowl immediately above the point 42, corresponds to the contour of the bowl at the lower section of the riilles and diverges quite materially from the contour of the bowl immediately below the point 42. The contour of the lower part of the bowl is found advantageous in the recovery of certain values, but'at the lower part of the bowl the centrifugal force is less than at the point 42. In the recovery of certain values, while the contour of the lower portion of the bowl is advantageous, the centrifugal force is not sufficient and, therefore, I provide, above the point 42, a substantial duplicate of the contour of the lower portion of the bowl but I provide this at a point where the centrifugal force is much greater, with the result that different classes of material may be recovered above the point 42 than can be recovered either at the bottom of the bowl, which has the same contour as the portion of the bowl above the point 42, or at the portion of the bowl just below point 42 which has substantialy the same centrifugal force as the portion immediately above point 42, but which has a different contour. Similarly in the embodiment shown in Figs. 5 to 7, I substantially duplicate in section 1a the contour of the lower portion of thebowl 1, but at a point where the centrifugal force exerted upon the material is much greater.

It will be understood that in larger sizes of the apparatus, it may be found desirable to provide suitable means for steadying the bowl at thebottom against vibration. Any suitable means for that purpose may be provided as many disclosed heretofore having such means and as such steadying means form no part of the present invention they are not here shown but will readily occur to those skilled in the art, as will likewise readily occur such changes as are necessary in the construction here disclosed in order to accommodate such steadying means.

Having described the embodiments of my invention illustrated in the accompanying drawings, I shall now briefly describe the operation thereof.

Referring to Fig. 3, when operation is commenced the ring 9 is seated upon the bowl and this ring and the riflie basket are `in position shown in Fig. 3, in which position the bowl, with its associated mechanismshown in this'V figure, is revolved and thereupon thev material to be treated, consisting of placer material or ground ore and water, is fed to the lower central part of the bowl through any suitable supply means, as conduit 43. It will be understood that the placer material or ground ore and the water, are separately fed into some point in said conduit and that means for regulating the respective quantities thereof are provided. Any suitable structure well known and in common use may be provided for this purpose and as such structures are in common use the same are not disclosed here.

As the material enters the bottom of the bowl the raised central portion 6 deflects the material away from the center and the centrifugal force of the revolving bowl throws the material up along the sides of the bowl and the values are concentrated in the riffles, according to common practice in the use of centrifugal bowl separators. Different grades or classes of material will be collected in the riles at different points along .flow out over apron 13 into ues recovered the side of the bowl according to the values contained in the material and the varying contour of the bowl and the increase in the centrifugal force applied to the material as it approaches the rim of the bowl.

The waste material or gangue, passes over the top of the ring 9 and out over the apron 14 into the launder 32. It will be understood that any suitable settling means in common use may be provided outside of the launder 32 in any case where values may be left in the gangue or waste material. A tank 36 may be used.

After the above operation has been continued for the desired length of time or until the rifiles are suiiciently lled, the revolution of the bowl is continued but the lever 26 is depressed, resulting in raising the ring 9 and opening the space between the rim of the bowl proper and the ring 9 and also in raising the riflie basket from the bowl, whereupon it is obvious that the material gathered under the riifles or rings 'l and against the wall of the bowl will, by centrifugal force, be thrown upwardly along the smooth sides of the `bowl to the rim of the bowl and thence will the launder 34, thence through spout 35 and into the settling tank 36. It will be understood that when the clean-up operation starts, water alone will be supplied through the conduit 43, the supply of solid material being out off during the clean-up operation. It is obvious, however, that the clean-up operation will be almost instantaneous and that the centrifugal force of the-'bowl will almost immediately throw all of the material theretofore held by the riilles, up the sides of the bowl an out over apron 13, so that the period during which the supply of solid material to the machine is out o will be exceedingly brief and, therefore, there will be no substantial interruption of the concentrating operation of the apparatus in order to make a clean-up.

It will be obvious that recoveries will be of different kinds or classes at the different sections or zones of the bowl, according to the variations in the contour of the bowl and the centrifugal force and that these again will vary with the nature of the material treated. Whatever the differences in any given case between the recoveries at different sections or zones of the bowl, the same differences may be maintained in the clean-up or final recovery of the concentrated material by reason of the division of the bowl into separable sections, as illustrated in Figs. 5, 6 and 7 and as described hereinabove. The valin the bowl below the rst point of division will be separately recovered over the apron 13 in the launderfi. The values concentrated in the section la will be recovered and kept separate by means of the launder 34a and it will be obvious that the division of the bowl and the corresponding riiiies into separable sections rnay be multiplied as desired, thereby increasing the refinement of classification in the recovery and nal clean-up.

It will also be obvious that the rings 7 may be formed in any desired shape and that the riiile basket, whatever the form of the riiiles, may be produced more economically than riiiles or" similar shape can be cut in the inner surface of the bowl and it will also be obvious that wear and damage to the riiile basket can be repaired or the parts replaced with much less expense than in the case of riilies formed directly in the inner surface of the bowl. .Moreoven in case of wear and damage to the riilles, the use of the bowl itself would not be suspended, becausev a new riiile basket could be immediately placed within the bowl while the damaged or worn rillie basket is being repaired, whereas in the case of riflles formed in the bowl itself any repair or replacement would require suspension of operation of the whole machine during the making of such repair or replacement.

I state again that changes in detail, which will readily occur to those skilled in the art, may be made without departing from the spirit of the invention or scope of the appended claims.

I claim:

1. In a centrifugal separator, a rotatable flaresided bowl, rings normally contacting with the inner surface of the bowl and forming riilies thereon and means for breaking said contact and leaving a space between said rings and the inner surface of the bowl.

2. l'nV apparatus of the class described a flaresided bowl and means for rotating the saine to cause material in the bowl to be moved by centrifugal force outward and upward over the inner surface of the bowl, a rim-ring rotatable with the bowl and normally seated upon the rim of the bowl to prevent the escape of material over said rim, means for separating said ring and said rim, means forming riiies on the inner surface of the bowl when said ring is seated upon said rim and means for separating said riiiie-forming means from the inner surface of the bowl when said ring and said rim are separated whereby to remove obstruction to the movement of contained material over the inner surface of the bowl and over said rim.

3. In a centrifugal separator, a rotatable flaresided bowl having a rim-ring normally seated upon the bowl and normally constituting the material-discharge-rim thereof but separable therefrom to permit material to discharge from said bowl below said ring, means normally forming rilles on the inner iuface of said bowl to retain material therein and means for separating the ring and the rime-forming means from the bowl, to permit unobstructed passage of the contained material over the inner surface of the bowl and outwardly therefrom beneath said ring.

4. In a centrifugal separator, a rotatable flaresided bowl, a rim-ring normally seated upon the rim thereof, means carried by the ring adapted to normally contact with the inner surface of the bowl and form riiiles thereon and means, operable regardless of the rotation of rating said ring and rime-forming means from contact with the bowl.

5. In a centrifugal separator, a nare-sided bowl, rings normally contacting with the inner surface of the bowl and forming rilies 'thereon rotatable therewith, straps attached to and holding said rings in fixed inter-relative position and means, operable regardless of the rotation, for separating said rings from the inner surface of the bowl.

6. In a centrifugal separator, a rotatable flaresided bowl, a rim-ring normally seated upon the rim thereof and extending inwardly from said rim, means carried by the ring adapted to normally contact with the inner surface of the bowl and form riliies thereon and means, operable regardless or" the rotation of the bowl, for separating said ring and therewith the rifrle-forrning means from contact with the bowl.

7. In a centrifugal separator, in combination, a

rotatable bowl having a rim-ring normally seatedupon the bowl and normally constituting the material-discharge-rm thereof, means for separatthe bowl, for sepalll ing the rim-ring from the bowl during the rotation ofthe bowl to permit material to discharge from said bowl below said ring, a launder to catch the material flowing over said ring when in normal position and a separate launder for catching material escaping from the bowl below the ring when the ring is raised.

8. In a centrifugal separator, in combination, a rotatable bowl having a rim-ring normally seated upon the bowl and normally constituting the material-discharge-rim thereof, means for separating the rim-ring from the bowl during rotation of the bowl to permit material to discharge from said bowl below said ring, a launder to catch the material flowing over said ring when in normal position, a separate launder for catching material escaping from the bowl below the ring when the ring is raised and a settling tank to receive material from said second launder, said settling tank having a cover spaced from the walls of the tank to permit the overflow of liquid, but lockable to prevent access to the settlings in said tank.

9. In a centrifugal separator a rotatable flaresded bowl having the upper portion of its sides divided into annular sections, a rim-ring, normally seated upon the top of said sections, said rim-ring sections and body of bowl normally being in closed interrelation and constituting a single bowl with the top of said ring constituting the discharge rim of the bowl, means normally forming rifes on the inner surfaces of the bowl and of each of said sections thereof to retain material therein, means operable during rotation of the bowl for separating said rim-ring and its associated rime-forming means from the top annular section of the bowl and means for separating each of said annular sections with its associated riffleforming means from the next lower portionof the bowl.

10. In a centrifugal separator a rotatable flaresided bowl having the upper portion of its sides divided into annular sections, a rim-ring normally seated upon the top of said sections, said rim-ring, sections and body of bowl normally being in closed interrelation and constituting a single bowl with the top of said ring constituting the discharge rim of the bowl, means carried by the ring adapted to form riies on theinner surface of the uppermost of said annular sections when the ring is seated thereon, means carried by each of such annular sections adapted to normally form rifiles on the inner surface of the next lower section of the bowl and means for separating the ring and each section, together with the rime-forming means carried thereby, from the next lower portion of the bowl.A

11. In a centrifugal separator, a rotatable aresided bowl having the upper portion of its sides divided into annular sections, a rim-ring normally seated upon the top'of said sections, said rimring, sections and body of bowl normally being in closed interrelation and constituting a single bowl with the top of said ring constituting the discharge rim of the bowl, means normally forming rifes on the inner surfaces of the bowl and of each of said sections thereof to retain material therein, means for separating said rim-ring and its associated rime-forming means from the top annular section of the bowl and means for separating each of said annular sections with its associated rime-forming means from the next lower portion of the bowl, the inner lower'edge of such annular section being of smaller radius than the portion of the bowl normally adjoining such section therebelow.

12. In a centrifugal separator, a rotatable bowl having the upper portion of its sides divided into annular sections, a rim-ring normally seated upon the top of said sections, said rim-ring, sections and body of bowl normally being in closed interrelation and constituting a single bowl with the top of said ring constituting the discharge rim of the bowl, means normally forming riiiles on the inner surfaces of the bowl and of each of said sections thereof to retain material therein, means for separating said rim-ring and said riflie forming means from the top annular section of the bowl and means for separating from the portion of the bowl immediately therebelow, each of said annular sections and the means normally forming the riiiles in said next lower portion of the bowl, the inner lower edge of each such annular section being of smaller radius than the portion of the? bowl normally adjoining such section therebelow,

' and the contour of the inner surface of each such annular section being upon a larger radius than but otherwise a substantial duplicate of the contour of the lowest rifed portionof the bowl.

13. In a centrifugal separator, a rotatable bowl having its upper portion composed of annular members normally seated one upon another and upon the bottom portion of the bowl to form a complete bowl, said members being vertically sep-z arable from each other and from the body of the bowl and means for separating said members from each other and from the body of the bowl, said means comprising a frame rotatable with said Y bowl and adapted to liftingly engage said annulari members when said frame is lifted and means for lifting said frame.

14. In a centrifugal separator, a rotatable bowl having'an annular apron surrounding its rim, an annularV member normally seated upon said rim and means for lifting said annular member out of engagement with the rim of said bowl, said means being rotatable with said bowl and comprising rods engaging said annular member, and slidably engaging the apron on the rim of the bowl, a bracket connecting said rods, a bearing beneath said bracket and means for lifting said bearing into engagement with and thereafter to raise said bracket and thereby to raise said rods and annular member, the top portion of said bearing forming a contact with said bracket and being adapted to rotate when in engagement therewi h.

15. In a centrifugal separator, a rotatable bowl having an annular apron surrounding its rim, an'

annular member normally seated upon said rim and means for lifting said annular member out of engagement with the rim of said bowl, said means being rotatable with said bowl and comprising rods engaging said annular member and slidably engaging the apron on the rim of the bowl, a bracket connecting said rods, means, fixed against rotation with the bracket, for raising the bracket whereby to raise said annular member, and resilient means normally depressing said bracket each other and from the lower portion of said bowl, said means being rotatable with said bowl and comprising rods engaging the uppermost ann nular member and slidably engaging the said aprons, collars upon said rods for liftingly engaging the apron of the lower annular member and means for raising said rods to lift said annular members while in rotation.

17. In a centrifugal separator, a rotatable flare-sided bowl, means insertable in said bowl and normally contacting with the inner surface thereof to form riles thereon, said rime-forming means being carried by a member rotatable with said bowl, said rifiie forming means being separable from said bowl.

18. In a centrifugal separator, a flare-sided bowl, rings normally contacting with the inner surface of the bowl and forming ries thereon and means for breaking said Contact and leaving a space between said rings and the inner surface of the bowl while the bowl is rotating.

19. In a centrifugal bowl separator, rings normally contacting with the inner surface of the bowl and forming rimes thereon and means for separating the riilies and the inner surface of the bowl by a movement of one of said elements at an acute angle to the contour of the inner surface of the bowl.

CHASE E. GISI-, 

